Corthylus granulosus Atkinson, 2020

Atkinson, Thomas H., 2020, New species, new records and synonymy of Mexican Corthylus Erichson, 1834 (Coleoptera: Curculionidae: Scolytinae), Insecta Mundi 2020 (792), pp. 1-25 : 20-22

Corthylus granulosus Atkinson , new species

Fig. 14 A–D

Diagnosis. This species would key to couplet 19 in Wood’s 1982 key or to couplet 32 depending on how the small postero-lateral margin of the declivity in interpreted. In either case the key would fail beyond that point. It most closely resembles species that would key out to couplet 6, but would not go further. It would key to couplet 37 in his 2007 key but would not match either alternative. Distinctive characters include the evenly convex declivity

with abundant granules and setae on the entire declivital face. The female frons is unusual in having two separate, elongate, yellow waxy or finely pilose areas.

Female. Length: 1.87 mm, maximum width: 0.75 mm; length of elytra: 1.1 mm; length to width: 2.5; elytral length/total length: 0.59; elytral length/width: 1.47. (n = 1).

Frons shallowly concave from epistoma to vertex; lateral areas with yellowish, finely pilose or waxy appearance on either side to slightly above upper level of eyes. Center of frons from epistoma to vertex impunctate, shining; lateral areas, especially above deeply, closely punctured. Short, sparse setae on upper lateral margins of frontal concavity. Antenna rounded, asymmetrical. Sutures 1 and 2 marked externally by distinct grooves; suture 1 appears aseptate in the unique type.

Anterior margin of pronotum rounded, unarmed. Anterior slope with flattened asperities to summit, Disc smooth, shining, with widely spaced, shallow punctures, most with a short recumbent seta.

Elytral disc smooth, shining. Strial and interstrial punctures similar in size, confused near base, mostly without associated setae.

Declivity convex in lateral profile. A distinct, short ridge on postero-lateral margin from apex to about interstria 7. All striae and interstriae confused on face of declivity. Punctures replaced with small rounded granules, each associated with a fine, curved, acuminate seta. Interstriae 2 slightly impressed, interstriae 3 not elevated.

Male. Unknown.

Type material. Holotype female. Mexico: Chiapas: Chiquihuites , 15.0936 N, 92.0994 W, 1,990 m, 5-11-V-2013, F. Infante ( CNIN).

Etymology. The name reflects the abundant granules over the entire surface of the declivity.

Figures

Figure 14. Corthylus granulosus, new species, female holotype. A) Dorsal habitus. B) Lateral habitus. C) Frons and antenna. D) Declivity. All photographs by the author